My guess is that liberating the fossil fuel industry to frack anywhere they want will drive down the rate at which we're converting to sun and wind. And it's entirely a rate problem at this point.

I don't spend a huge amount of time fixated on climate denial because I don't think that their objections, though sometimes couched in science, are based in science. I think they're based in ideology. And I don't think there's anything you can do.

It's off the charts - and if you don't believe the scientists, ask the insurance industry, the people we pay to analyze risk in our society.

[Kids] will grow up into a world that's difficult and wonderful, and they'll make the best of it they can, and hopefully help turn it in the best possible direction.

I guess the underlying principle might be, don't make it too easy for them to stereotype you.

We finally know where the red line for climate really is. After the rapid melt of arctic ice in the summer of 2007, our best scientists, led by NASA's Jim Hansen, went back to work and produced a series of papers showing that with more than 350 ppm (parts per million) of carbon dioxide in the atmosphere, we couldn't have a planet "similar to the one on which civilization developed and to which life on earth is adapted."

There is an urgent need to stop subsidizing the fossil fuel industry, dramatically reduce wasted energy, and significantly shift our power supplies from oil, coal, and natural gas to wind, solar, geothermal, and other renewable energy sources.